We have a Trane Weathertron Xl1200 heating pump with the thermostat pictured below and are trying to replace it with our new Nest thermostat. Our old system has a variable speed air handler and we want to make sure that we hooked up the wiring correctly. We have electric heat with emergency backup. Is the wiring we have correct or do we need to change anything? We have the latest version of the Nest thermostat.
Here's the 1 Stage heat Pump with Aux heat and Emergency heat from the Nest Pro Installer Guide.
Your diagram is close, but Nest suggests to use Rc (it should internally jump Rc and Rh if necessary) and W -> W2/Aux.
Note - variable speed fans are not supported, so proceed at risk.